* Test your thermometer in boiling water. If the water boils at a temperature other than 212°F, adjust the temperature accordingly.* If your toffee separates during cooking, carefully and slowly add about 1/2 cup hot water, 1 tablespoon at a time, and stir constantly.* If you prefer a thinner toffee, use two buttered (15 x 10 x 1-inch) pans or cookie sheets and pour half of toffee mixture on each; spread to desired thickness.